Question

me ajudem gentee por favor

Answer 1

$Area(trapezio)=\frac{(base\;maior\;+\;base\;menor)*altura}{2} \\\\Area = 160cm^2\\\\Base\;menor=12cm\\\\altura=x\\\\base\;maior=2*altura=2x\\\\Substituindo\;os\;dados:\\\\160=\frac{(12+2x)*x}{2}\\ \\320=12x+2x^2\\\\2x^2+12x-320=0\\\\Aplicando\;Bhaskara:\\x_1=10\\\\x_2=-16\\\\Cmo\;nao\;podemos\;ter\;medidas\;negativas,\;podemos\;descartar\;x_2.\\\\Como\;x=10\;podemos\;achar\;o\;valor\;da\;base\;maior:\\\\Base\;maior=2x=2*10=20cm\;(letra\;A))$

Answer 2

A= (B+b).h

__----------
_____2

160=( 2h+12).h
___--------------
______2

320= 2h^2+12h

2h^2+12h-320=0

h^2+6h-160=0

∆= b^2-4.a.c

∆= (6)^2-4.1.(-160)
∆= 36+640
∆= 676

x= -b+-√∆
---------------
____2.a


x= -(+6)+-√676
--------------------
____2.1


x'= -6+26
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____2


x'= 20/2
x'= 10

x"= -6-26
--------------
____2


x"= -32/2
x"= -16


base maior vale 20 cm


A= (20+12).10
-------------------
_____2


A= 32.10
-------------
____2


A= 320/2

A= 160 cm^2